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Course: Health and medicine > Unit 13
Lesson 1: Bacteria and viruses- Overview of Archaea, Protista, and Bacteria
- Bacterial characteristics - Gram staining
- Antibiotics
- Antibiotics: An overview
- What is antibiotic resistance?
- Bacterial meningitis
- Virus structure and classification
- Viral replication: lytic vs lysogenic
- Retroviruses
- Subviral particles: viroids and prions
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Antibiotics
What are antibiotics and where do they come from?
This article offers and overview of the origin and applications of antibiotics.
Key terms
| term | meaning |
|---|---|
| infection | invasion of organism by disease-causing microorganism |
| antibiotic | substance that inhibits growth of or kills bacteria |
| antibiotic resistance | ability of bacteria to remain unaffected by antibiotics |
An introduction to antibiotics
The image below shows the life expectancy in different parts of the world over a few hundred years. Can you spot the point of time at which something interesting happens?
As you might have noticed, life expectancy started to dramatically increase towards the late
If you've ever had an ear or throat infection, chances are that your doctor prescribed you some antibiotics. Before the discovery of antibiotics, these infections could become so severe that they killed people. Once scientists figured out how to use antibiotics, the probability of dying from such infections reduced dramatically (as seen in the above image).
Read on to find out more about where antibiotics come from, and how they help fight infection.
What are antibiotics and where do they come from?
Antibiotics are substances that can prevent the growth of some microorganisms. The word itself literally translates to 'against life'. The image below is a picture of a bacterial growth being inhibited on a culture dish by antibiotics.
Here's where things get interesting - they are produced by microorganisms! Certain fungi and bacteria can make several types of antibiotics. In the case of fungi, these substances help protect them against infection. The first ever antibiotic was , which are a type of fungus. But most of the antibiotics that we use today actually come from a type of soil bacteria called Streptomyces.
How do antibiotics work?
Different types, or classes, of antibiotics work in different ways. The common mechanism usually involves the antibiotic entering the bacterial cell and then getting in the way of one or more process inside it. This can lead either to the death of the bacterium, or delay or prevent it from replicating.
For example, one type of antibiotic interferes with the production of bacterial cell walls. This makes the bacterial cell leaky, allowing water to it until it swells and eventually bursts, killing the bacterium.
Another class of antibiotics can stop the bacterium from creating RNA, which brings its entire cellular machinery to a stop - leading to its death.
Another class of antibiotics can stop the bacterium from creating RNA, which brings its entire cellular machinery to a stop - leading to its death.
Antibiotics that do not kill bacteria usually inhibit protein synthesis or DNA replication. This makes it hard for the bacterium to replicate, thus interfering with their growth.
Antibiotic resistance
A word of warning - bacteria can evolve very quickly and the excessive use of antibiotics (especially when not required) can lead to antibiotic resistance. In these cases, the bacteria are either less or no longer affected by antibiotics, and become 'super bugs' that are hard to treat successfully.
Want to join the conversation?
Should we even use or create antibiotics? Is the evidence clear that bacterial infections ought to be cured with effort, and aren't as natural as natural selection? Sorry for this question, but I'm asking with an open mind, to know the truth. I'm not defending any stance, and I myself know antibiotics are lifesaving.(9 votes)
Fantastic, antibiotics serves as greatest weapon that helps to fight against bacterias, natural and artificials are now variations with us even after resseliences that they may develop but we would have alternative sollutions as in natural artificials too , numorous variations could be made by biotech buddy ,so technicAAlly we are one step ahead ,,(1 vote)
This was a good artical(3 votes)